PC Motors and Motor Controls

Question 1

Which NEC article covers motors, motor circuits, and controllers?

Accepted Answer

Article 430

Answer

Article 440

Answer

Article 450

Answer

Article 460

Question 2

What is the minimum ampacity required for branch circuit conductors supplying a single continuous-duty motor?

Accepted Answer

125% of motor FLA

Answer

100% of motor FLA

Answer

115% of motor FLA

Answer

150% of motor FLA

Question 3

Which device provides both overload protection and short-circuit protection for a motor in a single assembly?

Accepted Answer

Combination motor controller

Answer

Thermal overload relay

Answer

Fused disconnect switch

Answer

Manual motor starter

Question 4

Per NEC Table 430.52, what is the maximum inverse time circuit breaker rating for a Design B motor with an FLA of 40A?

Accepted Answer

100A

Answer

50A

Answer

75A

Answer

150A

Question 5

What is the primary purpose of a motor overload relay?

Accepted Answer

To protect motor windings from damage due to overheating

Answer

To protect against short circuits in the branch circuit

Answer

To provide ground fault protection for personnel

Answer

To protect against voltage surges from the utility

Question 6

A motor has a nameplate FLA of 20A and a service factor of 1.15. What is the maximum overload protection rating per NEC 430.32?

Accepted Answer

26A (130%)

Answer

23A (115%)

Answer

25A (125%)

Answer

28A (140%)